Biosensor using magnetic nanoparticles, and detection device and detection method using same

ABSTRACT

According to one embodiment of the present application, a biosensor, the biosensor comprising: a reaction part including a magnetic nanoparticle complex, a first electrode, and a second electrode; and a sample introduction part forming a passage so that a sample can be introduced into the reaction part from an outside of the biosensor; wherein the magnetic nanoparticle complex includes a first capturing substance for capturing a first target substance, a magnetic nanoparticle, and a reaction substance that performs at least one of an oxidation reaction and a reduction reaction, wherein the magnetic nanoparticle complex is magnetic in the reaction part, and has a property that mobility can be changed according to a change in a condition of the reaction part, wherein the first electrode, a second capturing substance for capturing a second target substance is fixed, wherein the second electrode is an electrode different from the first electrode, and characterized in that at least one of the first target substance and the second target substance is included in the sample, may be provided.

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

Any and all applications for which a foreign or domestic priority claimis identified in the Application Data Sheet as filed with the presentapplication are hereby incorporated by reference under 37 CFR 1.57.

BACKGROUND Technical Field

Embodiments relate to a biosensor using magnetic nanoparticles.

Embodiments relate to a detection device using the biosensor.

Embodiments relate to a detection method of the detection device usingthe biosensor.

Description of the Related Art

With the advent of an aging society, as the demand for point-of-caretesting (POCT) for disease prevention and early diagnosis has increased,various on-site diagnostic kits such as biosensors using membranes andbiosensors using micro fluidic channels have been commercialized. Thedemand for these products is also increasing rapidly.

However, when compared with the disease diagnosis accuracy andsensitivity of an enzyme-linked immunospecific assay (ELISA) methodconducted by a person in a clinical trial room of a large hospital,there is a problem in that accuracy and sensitivity of disease diagnosisof the various on-site diagnostic kits have been significantly degraded.

One among causes degrading the accuracy and sensitivity of the diseasediagnosis is that backgrounds of a sample and the like degrade detectionaccuracy. This remains as a chronic problem because it is difficult toremove the backgrounds without additional and costly device design orhuman washing due to the nature of the biosensor in which movement andreaction of a sample are performed by a capillary force withoutprovision of an extra external force.

Thus, there is a need for a part for washing unnecessary reactants on anon-site diagnostic kit through a simple method to remove a backgroundand improve detection accuracy and detection sensitivity.

SUMMARY Technical Problem

Embodiments are directed to providing a biosensor for solving a problemin that accuracy is degraded due to a background.

Embodiments are also directed to providing a biosensor with improveddetection sensitivity by stabilizing a detected signal.

Technical Solution

According to one embodiment of the present application, a biosensor, thebiosensor comprising: a reaction part including a magnetic nanoparticlecomplex, a first electrode, and a second electrode; and a sampleintroduction part forming a passage so that a sample can be introducedinto the reaction part from an outside of the biosensor; wherein themagnetic nanoparticle complex includes a first capturing substance forcapturing a first target substance, a magnetic nanoparticle, and areaction substance that performs at least one of an oxidation reactionand a reduction reaction, wherein the magnetic nanoparticle complex ismagnetic in the reaction part, and has a property that mobility can bechanged according to a change in a condition of the reaction part,wherein the first electrode, a second capturing substance for capturinga second target substance is fixed, wherein the second electrode is anelectrode different from the first electrode, and characterized in thatat least one of the first target substance and the second targetsubstance is included in the sample, may be provided.

According to one embodiment of the present application, a detectiondevice, the detection device comprising: an electrode part capable ofbeing connected to a biosensor, wherein the biosensor includes amagnetic nanoparticle complex including a first capturing substance forcapturing a first target substance, a magnetic nanoparticle and areaction substance that performs at least one of an oxidation reactionand a reduction reaction, a first electrode to which the second targetsubstance for capturing a second target substance is fixed, and a secondelectrode different with the first electrode, and wherein at least oneof the first target substance and the second target substance areincluded in a sample, and a control unit for controlling to provide avoltage including a first step of raising the voltage applied betweenthe first electrode and the second electrode and a second step offalling the voltage, in order to detect whether the second targetsubstance is captured in the sample introduced into the biosensor bydetecting a current according to a change in the applied voltage, and toprovide a voltage that applies a voltage higher than a minimum voltageof at least one of the lowest voltage in the first step and the lowestvoltage in the second step for a predetermined time or longer, in orderto stabilize the curve of the current, before providing a voltage toinclude the first step and the second step, may be provided.

Advantageous Effects

According to embodiments, it is possible to provide a biosensor whichsolves a problem in that accuracy is degraded due to a background,through washing performed by changing an environmental condition in areaction part.

According to the embodiments, it is possible to provide a biosensor withimproved detection sensitivity by providing a voltage for stabilizing asignal prior to a detection operation.

The effects of the present application are not limited to theabove-described effects, and effects not mentioned will be apparentlyunderstood by those skilled in the art from the present specificationand the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram for describing a detection system (1) according toone embodiment of the present application.

FIG. 2 is a diagram for describing a biosensor (1000) according to oneembodiment of the present application.

FIG. 3 is a diagram for describing a reaction part (1200) according toone embodiment of the present application.

FIG. 4 is a diagram for describing a magnetic nanoparticle complex(1210) according to one embodiment of the present application.

FIG. 5 is a diagram for describing a first electrode (1220) according toone embodiment of the present application.

FIG. 6 is a diagram for describing a general operation of the biosensor(1000) according to one embodiment of the present application.

FIG. 7 is a diagram for describing an operation of a biosensor (1000)according to a first embodiment of the present application.

FIG. 8 is an enlarged view for describing an arrangement of a thirdelectrode for providing a magnetic field according to one embodiment ofthe present application.

FIG. 9 is a graph for describing a variation in current over a voltageof the biosensor (1000) including a first electrode (1220) to whichbovine serum albumin (BSA) is fixed according to one embodiment of thepresent application.

FIG. 10 is a diagram for describing a detection device (2000) accordingto one embodiment of the present application.

FIG. 11 is a diagram for describing an operation of the detection device(2000) according to one embodiment of the present application.

FIG. 12 is a diagram for describing an operation of providing a secondsignal (S2000) according to one embodiment of the present application.

FIG. 13 is a diagram for describing an operation of providing asecond-third signal (S2300) according to one embodiment of the presentapplication.

FIG. 14 is a diagram for describing an operation of performing areduction pretreatment prior to the operation of providing of thesecond-third signal (S2300) according to a third embodiment of thepresent application.

FIG. 15 is a diagram for describing a detection graph of a third signalaccording to an operation of providing a second-second signal (S2200)and the operation of providing of the second-third signal (S2300)according to one embodiment of the present application.

FIG. 16 is a diagram for describing an operation of performing oxidationpretreatment prior to the operation of providing of the second-thirdsignal (S2300) according to a fourth embodiment of the presentapplication.

DETAILED DESCRIPTION Modes of the Invention

The above-described purposes, features and advantages of the presentapplication will become more apparent through the following detaileddescription in connection with the accompanying drawings. However, thepresent application may be modified in various ways and may have variousembodiments. Hereinafter, specific embodiments will be illustrated inthe drawings and described in detail.

In the drawings, the thickness of the layers and regions are exaggeratedfor clarity. What an element or layer is referred to as “on” or “on” ofanother component or layer is not only directly above the othercomponent or layer, but also another layer or other component in themiddle. Therefore, the meaning of “on” includes both of the case.Throughout the specification, the same reference numbers refer to thesame components in principle. In addition, elements having the samefunctions within the scope of the same idea appearing in the drawings ofthe respective embodiments will be described using the same referencenumerals.

If it is determined that a detailed description of known functions orconfigurations related to the present application may unnecessarilyobscure the subject matter of the present application, the detaileddescription will be omitted. In addition, the numbers used in thedescription process of the present specification (eg, first, second,etc.) are merely identification symbols for distinguishing one componentfrom other components.

In addition, the suffixes “module” and “part” for components used in thefollowing description are given or mixed only considering the ease ofwriting the specification, and do not have a meaning or a role that isdistinguished from each other.

According to one embodiment of the present application, a biosensor, thebiosensor comprising: a reaction part including a magnetic nanoparticlecomplex, a first electrode, and a second electrode; and a sampleintroduction part forming a passage so that a sample can be introducedinto the reaction part from an outside of the biosensor; wherein themagnetic nanoparticle complex includes a first capturing substance forcapturing a first target substance, a magnetic nanoparticle, and areaction substance that performs at least one of an oxidation reactionand a reduction reaction, wherein the magnetic nanoparticle complex hasis magnetic in the reaction part, and has a property that mobility canbe changed according to a change in a condition of the reaction part,wherein the first electrode, a second capturing substance for capturinga second target substance is fixed, wherein the second electrode is anelectrode different from the first electrode, and characterized in thatat least one of the first target substance and the second targetsubstance is included in the sample, may be provided.

A biosensor, wherein the magnetic nanoparticle is modified to expose areactor to an outside of the magnetic nanoparticle, characterized inthat the reaction substance is fixed to the reactor, may be provided.

A biosensor, wherein the biosensor characterized in that the reactor isan amine, and the reaction substance is gold, may be provided.

A biosensor, wherein the biosensor characterized in that the firstcapturing substance is fixed to the reaction substance fixed to thereactor, may be provided.

A biosensor, wherein a blocking substance that prevents adsorption ofthe second target substance is disposed in at least a portion of thefirst electrode, may be provided.

A biosensor, wherein the biosensor characterized in that the blockingsubstance is a BSA (Bovine Serum Albumin), may be provided.

A biosensor, wherein the first capturing substance includes at least oneof an antigen, an antibody, a modified antibody, an antibody analog, anaptamer, a nucleic acid, a lipid, and a viral protein antigen, andwherein the second capturing substance includes at least one of theantigen, the antibody, the modified antibody, the antibody analog, theaptamer, the nucleic acid, the lipid, and the viral protein antigen, maybe provided.

A biosensor, wherein the first target substance is same substance withthe second target substance included in the sample, and wherein thefirst capturing substance is same substance with the second capturingsubstance, may be provided.

A biosensor, wherein the first target substance is the second targetsubstance fixed on the first electrode, wherein the second targetsubstance is the same substance with the first capturing substance, andcharacterized in that the first capturing substance is included in thesample, may be provided.

A biosensor, wherein the first target substance is the second targetsubstance fixed on the first electrode, wherein the second targetsubstance is the same substance with the first capturing substance, andcharacterized in that the second capturing substance is included in thesample, may be provided.

A biosensor, when a magnetic field formed in the reaction part, whereina direction of a movement of the magnetic nanoparticle complex ischanged, may be provided

A biosensor, when a voltage applied between the first electrode and thesecond electrode is changed, wherein a direction of a movement of themagnetic nanoparticle complex is changed, may be provided.

A biosensor, wherein the biosensor further comprising a third electrodehaving a coil shape different from the first electrode and the secondelectrode, and when a current applied to the third electrode is changed,wherein a direction of a movement of the magnetic nanoparticle complexis changed, may be provided.

A biosensor, wherein the biosensor, at least a portion of a fourthelectrode electrically connected to the first electrode and at least aportion of a fifth electrode electrically connected to the secondelectrode are exposed to the outside of the biosensor, may be provided.

A biosensor, wherein the first electrode and the fourth electrode arecomposed of one electrode, and wherein the second electrode and thefifth electrode are composed of one electrode, may be provided.

A biosensor, wherein at least a portion of fourth electrode and at leasta portion of fifth electrode are electrically connected to a devicecapable of measuring a current, may be provided

A biosensor, wherein a voltage applied between the first electrode andthe second electrode is controlled by the device, wherein, according tocurrent by applying the voltage between the first electrode and thesecond electrode, capable of detecting whether the second targetsubstance is included in the sample, may be provided.

According to one embodiment of the present application, a detectiondevice, the detection device comprising: an electrode part capable ofbeing connected to a biosensor, wherein the biosensor includes amagnetic nanoparticle complex including a first capturing substance forcapturing a first target substance, a magnetic nanoparticle and areaction substance that performs at least one of an oxidation reactionand a reduction reaction, a first electrode to which the second targetsubstance for capturing a second target substance is fixed, and a secondelectrode different with the first electrode, and wherein at least oneof the first target substance and the second target substance areincluded in a sample, and a control unit for controlling to provide avoltage including a first step of raising the voltage applied betweenthe first electrode and the second electrode and a second step offalling the voltage, in order to detect whether the second targetsubstance is captured in the sample introduced into the biosensor bydetecting a current according to a change in the applied voltage, and toprovide a voltage that applies a voltage higher than a minimum voltageof at least one of the lowest voltage in the first step and the lowestvoltage in the second step for a predetermined time or longer, in orderto stabilize the curve of the current, before providing a voltage toinclude the first step and the second step, may be provided.

A detection device, wherein the first capturing substance includes atleast one of an antigen, an antibody, a modified antibody, an antibodyanalog, an aptamer, a nucleic acid, a lipid, and a viral proteinantigen, and wherein the second capturing substance includes at leastone of the antigen, the antibody, the modified antibody, the antibodyanalog, the aptamer, the nucleic acid, the lipid, and the viral proteinantigen, may be provided.

A detection device, wherein the first capturing substance is samesubstance with the second capturing substance, wherein the first targetsubstance is same substance with the second target substance, andwherein the first target substance is including in the sample, may beprovided.

A detection device, wherein the control unit controls to provide thevoltage that the voltage between the first electrode and the secondelectrode is raised from at least 0 V to at least 1 V, in the firststep, and controls to provide the voltage that the voltage between thefirst electrode and the second electrode is fallen from at least 1 V toat least 0 V, in the second step, may be provided.

A detection device, wherein the control unit controls to provide thevoltage applied by the voltage of at least 1 V for at least 2 secondsbetween the first electrode and the second electrode, in order tostabilize the curve of the current, may be provided.

A detection device, wherein the control unit, for stabilizing the curveof the current, after controlling to provide the voltage applied by thevoltage of at least 1 V for at least 2 seconds between the firstelectrode and the second electrode, controls to provide the voltage thatthe voltage between the first electrode and the second electrode isfallen from at least 1 V or more to at least 0 V or less, may beprovided.

A detection device, wherein the control unit, for stabilizing the curveof the current, after controlling to provide the voltage that thevoltage between the first electrode and the second electrode is fallenfrom at least 1 V or more to at least 0 V or less, controls to providethe voltage that the voltage between the first electrode and the secondelectrode is raised from at least 0 V or less to at least 1 V or more,may be provided.

A detection device, wherein the control unit, for stabilizing the curveof the current, after controlling to provide the voltage applied by thevoltage of at least 1 V for at least 2 seconds between the firstelectrode and the second electrode, controls to provide the voltage thatthe voltage between the first electrode and the second electrode israised from at least 0 V or less to at least 1 V or more, may beprovided.

According to one embodiment of the present application, a detectionmethod of a detection device electrically connected to a biosensorincluding a magnetic nanoparticle complex including a first capturingsubstance for capturing a first target substance, a magneticnanoparticle and a reaction substance that performs at least one of anoxidation reaction and a reduction reaction, a first electrode to whichthe second target substance for capturing a second target substance isfixed, and a second electrode different with the first electrode,wherein at least one of the first target substance and the second targetsubstance is included in a sample, the detection method comprising:providing a circulating voltage including a first step of raising avoltage applied between the first electrode and the second electrode anda second step of falling the voltage applied between the first electrodeand the second electrode, in order to detect whether the second targetsubstance in the sample introduced into the biosensor is captured bydetecting a current according to a change in the applied voltage; beforea step of providing the voltage, stabilizing a signal for applying thevoltage higher than at least one of a minimum voltage of the first stepand the minimum voltage of the second step for a predetermined period ormore to stabilize the curve of the current; and detecting the currentaccording to the first step and the current according to the secondstep, may be provided.

A detection method, wherein the first capturing substance includes atleast one of an antigen, an antibody, a modified antibody, an antibodyanalog, an aptamer, a nucleic acid, a lipid, and a viral proteinantigen, and wherein the second capturing substance includes at leastone of the antigen, the antibody, the modified antibody, the antibodyanalog, the aptamer, the nucleic acid, the lipid, and the viral proteinantigen, may be provided.

A detection method, wherein the first capturing substance is samesubstance with the second capturing substance, wherein the first targetsubstance is same substance with the second target substance,characterized in that wherein the first target substance is including inthe sample, may be provided.

A detection method, wherein the first step is a step in which thevoltage between the first electrode and the second electrode is raisedfrom at least 0 V to at least 1 V, and wherein the second step is a stepin which the voltage between the first electrode and the secondelectrode is fallen from at least 1 V to at least 0 V, may be provided.

A detection method, wherein the step of stabilizing the signal is,wherein the step of stabilizing the signal for applying the voltagehigher than at least one of the minimum voltage of the first step andthe minimum voltage of the second step for the predetermined period ormore further comprising: providing the voltage such that the voltage ofat least 1V is applied between the first electrode and the secondelectrode for at least 2 seconds, may be provided.

A detection method, wherein the step of stabilizing the signal isfurther comprising, after providing the voltage such that the voltage ofat least 1V is applied between the first electrode and the secondelectrode for at least 2 seconds, providing the voltage such that thevoltage between the first electrode and the second electrode is fallenfrom at least 1V or more to at least 0V or less, may be provided.

A detection method, wherein the step of stabilizing the signal isfurther comprising, after providing the voltage such that the voltagebetween the first electrode and the second electrode is fallen from atleast 1V or more to at least 0V or less, providing the voltage such thatthe voltage between the first electrode and the second electrode israised from at least 0V or less to at least 1V or more, may be provided.

A detection method, wherein the step of stabilizing the signal isfurther comprising, after providing the voltage such that the voltage ofat least 1V is applied between the first electrode and the secondelectrode for at least 2 seconds, providing the voltage such that thevoltage between the first electrode and the second electrode is raisedfrom at least 0V or less to at least 1V or more, may be provided.

Detection System 1

Hereinafter, a detection system 1 capable of detecting whether a targetsubstance is present in a sample will be described.

For example, the detection system 1 will be disclosed which is capableof detecting whether a target disease (that is, a disease to beconfirmed) is present in a sample such as blood, urine, adeoxyribonucleic acid (DNA) sample, or the like, which may be extractedfrom a human body, on the basis of the presence or absence of a specificantigen, an antibody, DNA, and/or ribonucleic acid (RNA) (that is, thepresence or absence of a target substance).

FIG. 1 is a diagram for describing a detection system 1 according to oneembodiment of the present application.

According to one embodiment of the present application, the detectionsystem 1 may include a biosensor 1000 and a detection device 2000.

The biosensor 1000 may include a biological receptor capable of beinginduced a specific reaction with a target substance contained in asample. The biosensor 1000 may be a device manufactured to detect thepresence or absence of the target substance in a sample, either alone orthrough the detection device 2000, involved in converting such the abovespecific reaction into an electrical or optical signal.

For example, the biosensor 1000 may be a micro fluid dynamics-basedbiosensor 1000 which is designed to allow a sample to move in a microfluidic channel due to an influence of surface tension of a fluid. Inthis case, the biosensor 1000 may be made of a material having rigidity.For example, the biosensor 1000 may include plastic and/or glass.

The biosensor 1000 according to one embodiment of the presentapplication will be described in more detail below.

The detection device 2000 may be a device for detecting a variation inan electrical, optical, magnetic, and/or thermal signal which is derivedfrom a result according to a reaction in the biosensor 1000 anddetermining the presence or absence of the target substance in thesample.

For example, the detection device 2000 may include an input port intowhich the biosensor 1000 is input and determine whether a targetsubstance is present in a sample introduced into the biosensor 1000 onthe basis of an electrical variation of the biosensor 1000.

The detection device 2000 may be a single device manufactured to detecta result value depending on the biosensor 1000 or may be a device havingother functions modified to detect the result value depending on thebiosensor 1000. For example, the detection device 2000 may be adetection device 2000 for the biosensor 1000, a mobile phone device ofwhich one region is modified to allow the biosensor 1000 to be input, ora device implemented in the form of being integrated with a householdappliance.

In addition, the present application is not limited to theabove-described example, and any detection device 2000 easily derivedfrom the disclosure of the detection device 2000, which will bedescribed below, according to one embodiment of the present application,may correspond to the detection device 2000 according to the presentapplication.

Biosensor 1000

1. Configuration of Biosensor 1000

FIG. 2 is a diagram for describing a biosensor 1000 according to oneembodiment of the present application.

The biosensor 1000 may include a sample introduction part 1100, areaction part 1200, and/or a contact part 1300. However, all the abovecomponents need not be included, and each component may be omitted orduplicated, and a biosensor 1000 may also be manufactured in the form offurther including components in addition to the above disclosedcomponents.

1.1 Sample Introduction Part 1100

The sample introduction part 1100 may be a region in which a sample isintroduced from the outside to the inside of the biosensor 1000. Inother words, the sample introduction part 1100 may be a region forming achannel which allows the sample to be introduced into the reaction part1200 which will be described below.

The sample may be a matter including a target substance. For example,the sample may be a secretion secreted from a living body. The samplemay be blood, plasma, serum, saliva, urine, or the like. As anotherexample, the sample may be a material obtained for a research purpose.The sample may be a DNA sample, an RNA sample, or the like obtained froman incident site or a DNA sample, an RNA sample, or the like extractedfrom an animal cell or a virus.

The sample provided to the sample introduction part 1100 may move in theinterior of the biosensor 1000. The sample provided to the sampleintroduction part 1100 may move from the sample introduction part 1100to the reaction part 1200.

The sample may move along a micro channel. The sample may move on amembrane. In addition to the above description, the sample providedthrough the sample introduction part 1100 may move according to amovement method implemented through various manners utilized in thebiosensor 1000.

1.2 Reaction Part 1200

The reaction part 1200 may be a region in which a specific reaction isperformed. The reaction part 1200 may be a region in which a specificreaction is performed between a target substance and a capturingsubstance for capturing the target substance in the biosensor 1000.

The target substance may be a material to be detected that is includedin the sample. For example, the target substance may be an antigen. Inother words, the target substance may be an antigen related to a diseasedetected in blood or the like of a patient with a disease. As anotherexample, the target substance may be DNA. In other words, the targetsubstance may be DNA of a virus detected in blood or the like of apatient with a disease.

The capturing substance may be a material which is specifically boundwith the target substance. For example, the capturing substance may bean antibody. The capturing substance may be an antibody which isspecifically bound with the antigen on the basis of an antigen-antibodyreaction. As another example, the capturing substance may be DNA. Thecapturing substance may be DNA which is specifically bound with the DNAon the basis of complementarity of a specific sequence.

FIG. 3 is a diagram for describing a reaction part 1200 according to oneembodiment of the present application.

The reaction part 1200 may include a magnetic nanoparticle complex 1210,a first electrode 1220, and/or a second electrode 1230. However, all theabove components need not be included, and each component may be omittedor duplicated, and a biosensor 1000 may also be manufactured to includethe reaction part 1200 in the form of further including components inaddition to the above disclosed components.

The first electrode 1220 may be disposed upstream from the secondelectrode 1230. Here, the term “upstream” may mean that the sample isdisposed at an upstream based on a movement direction from a positionintroduced through the sample introduction part 1100 to the reactionpart 1200. In this case, the first electrode 1220 may be closer to thesample introduction part 1100 than the second electrode 1230.

Alternatively, the first electrode 1220 may be disposed downstream fromthe second electrode 1230. Here, the term “downstream” may mean that thesample is disposed at a downstream based on the movement direction fromthe position introduced through the sample introduction part 1100 to thereaction part 1200. In this case, the second electrode 1230 may becloser to the sample introduction part 1100 than the first electrode1220.

Alternatively, the first electrode 1220 and the second electrode 1230may be disposed to face each other. The first electrode 1220 and thesecond electrode 1230 may have the same distance from the sampleintroduction part 1100.

The magnetic nanoparticle complex 1210 may be disposed upstream from thefirst electrode 1220. The magnetic nanoparticle complex 1210 may bedisposed upstream from the second electrode 1230. The magneticnanoparticle complex 1210 may be disposed upstream from the firstelectrode 1220 and the second electrode 1230.

Hereinafter, each component will be described in more detail.

1.2.1 Magnetic Nanoparticle Complex 1210

1.2.1.1 Meaning

FIG. 4 is a diagram for describing a magnetic nanoparticle complex 1210according to one embodiment of the present application.

The magnetic nanoparticle complex 1210 may include a magneticnanoparticle 1211, reaction substances 1212, and/or first capturingsubstances 1213. However, all the above components need not be included,and each component may be omitted or duplicated, and a magneticnanoparticle complex 1210 may also be provided in the form of furtherincluding components in addition to the above disclosed components.

The magnetic nanoparticle 1211 is a magnetic particle. Types of themagnetic nanoparticle 1211 may include iron oxide (Fe2O3 or Fe3O4),ferrite (having a form in which one Fe is changed from Fe3O4 intoanother magnetically related atom, for example, CoFe2O4 or MnFe2O4)),and/or an alloy (alloys with precious metals to solve an oxidationproblem caused due to magnetic atoms and increase conductivity andstability, for example, FePt, CoPt, and the like). For example, themagnetic nanoparticle 1211 may be a Fe2O3 particle having a size rangingfrom 200 nm to 500 nm and having a ferromagnetic property.

The reaction substance 1212 may be a material for performing at leastone of an oxidation reaction and a reduction reaction. The reactionsubstance 1212 is a material having high thermal conductivity andelectrical conductivity and may include a transition metal, apost-transition metal, and/or a metalloid. For example, the reactionsubstance 1212 may mean a gold (Au) particle. Alternatively, thereaction substance 1212 may mean a silver (Ag) particle.

The reaction substance 1212 may be fixed to the magnetic nanoparticle1211. For example, the reaction substance 1212 may be fixed to themagnetic nanoparticle 1211 through a chemical bonding force with themagnetic nanoparticle 1211. Alternatively, the reaction substance 1212may fixed to the magnetic nanoparticle 1211 by binding an amine groupexposed to the outside of the magnetic nanoparticle 1211.

The first capturing substance 1213 may be a material which isspecifically bound with a first target substance. For example, the firsttarget substance may be a target substance (that is, a material to bedetected, which is included in a sample). In this case, the firstcapturing substance 1213 may be a material which is specifically boundwith the target substance. Alternatively, the first target substance maybe a material which is specifically bound with the target substance. Inthis case, the first capturing substance 1213 may specifically bond to amaterial which is specifically competitively bound with the targetsubstance, competitively with the target substance.

The first capturing substance 1213 may include at least one among anantigen, an antibody, a modified antibody, an antibody analogue, anaptamer, nucleic acid (e.g., DNA, RNA), lipid, and a viral proteinantigen.

For a more specific example, when the first target substance is an“antigen,” the first capturing substance 1213 may be an antibody.Alternatively, when the first target substance is “DNA,” the firstcapturing substance 1213 may be single stranded DNA including a sequencewhich is complementarily bound with a single strand of the DNA (i.e., atarget substance).

The first capturing substance 1213 may be fixed to the reactionsubstance 1212. After the reaction substance 1212 is fixed to themagnetic nanoparticle 1211, the first capturing substance 1213 may bebound with the reaction substance 1212 to be fixed to the magneticnanoparticle 1211.

Thus, the magnetic nanoparticle complex 1210 includes the reactionsubstance 1212. When the magnetic nanoparticle complex 1210 is fixed ina region adjacent to the second capturing substance 1222 on the firstelectrode 1220, which will be described below, the magnetic nanoparticlecomplex 1210 is involved in varying a detection signal in the biosensor1000 so that it is possible to detect the presence or absence of thetarget substance using the biosensor 1000. The first capturing substance1213 of the magnetic nanoparticle complex 1210 is fixed through bondingwith the reaction substance 1212 and exposed to the outside of thereaction substance 1212 so that reactive degradation between the targetsubstance and the first capturing substance 1213 may be preventedbecause the reaction substance 1212 is included in the magneticnanoparticle complex 1210. A bonding degree of the reaction substance1212 is controlled according to an exposure degree of the amine group ofthe magnetic nanoparticle 1211 so that an optimal magnetic nanoparticlecomplex 1210, in which a magnetic property of the magnetic nanoparticlecomplex 1210 may not be extinguished, may be implemented.

Hereinafter, a method of synthesizing the magnetic nanoparticle complex1210 according to one embodiment of the present application will bedescribed in detail.

1.2.1.2 Synthesis Method

Hereinafter, a method of synthesizing the magnetic nanoparticle complex1210 using Au as a reaction substance 1212 and using an anti-prostatespecific antigen (PSA) detection antibody as the first capturingsubstance 1213 will be described. However, Au is merely an example ofthe reaction substance 1212 and the anti-PSA detection antibody ismerely an example of the first capturing substance 1213. It is obviousthat the reaction substance 1212 may be easily replaced with anotherreaction substance 1212 (e.g., Ag) and the first capturing substance1213 may be replaced with another first capturing substance 1213 (e.g.,an antigen, an antibody, DNA, or the like with respect to anotherdisease) by those skilled in the art.

In order to synthesize the magnetic nanoparticle complex 1210 accordingto one embodiment of the present application, 50 ml of a solutioncontaining 1 mg of the magnetic nanoparticle 1211 having a diameter of500 nm and modified into an amine group per 1 ml was subject toultrasonic treatment for one hour, and then 1 ml of a solutioncontaining 6 mg of HAuCl4.3H2O per 1 ml was added while theultrasonic-treated solution was continuously stirred on ice for onehour.

Thereafter, 0.2 ml of 0.2 M sodium borohydride was slowly added to thesolution, to which HAuCl4.3H2O was added, as a reducing agent andstirred for three hours. Then, the formed magnetic nanoparticle 1211 towhich Au was fixed was washed twice with deionized water (i.e., purifiedwater) and then stored at a temperature of 4° C. until further use.

The magnetic nanoparticle 1211, which is formed through the aboveprocedure and to which Au was fixed, was washed twice with a phosphatebuffered saline (PBS) solution. After the washing, the PBS solution wasdiscarded, and 10 mM dithiobis (succinimidyl propionate) (DSP) dissolvedin dimethyl sulfoxide (DMSO) was added to the magnetic nanoparticle, towhich Au was fixed, and incubated at room temperature for thirtyminutes. According to one embodiment of the present application, the DSPmay serve as a linker between Au and an anti-PSA detection antibody(i.e., one example of the first capturing substance 1213) which will beadded later.

Thereafter, the magnetic nanoparticle 1211, to which Au was fixed in theincubated solution, was washed with the PBS solution to remove anunbound DSP in the incubated solution. Then, an anti-PSA detectionantibody was added to the magnetic nanoparticle 1211, to which Au wasfixed, and incubated at room temperature for one hour and incubated at atemperature of 4° C. for sixteen hours.

The magnetic nanoparticle 1211 to which Au is fixed to which theanti-PSA antibody is fixed through the above procedure (i.e., themagnetic nanoparticle complex 1210) was washed twice with the PBSsolution and stored at a temperature of 4° C. until further use.

The magnetic nanoparticle complex 1210 according to one embodiment ofthe present application may be synthesized through the above procedure.The magnetic nanoparticle complex 1210 is provided in the biosensor 1000to react with the target substance included in the sample.

A detailed operation of the magnetic nanoparticle complex 1210 will bedescribed below.

1.2.2 First Electrode 1220

1.2.2.1 Meaning

FIG. 5 is a diagram for describing a first electrode 1220 according toone embodiment of the present application.

The first electrode 1220 is a conductive medium which emits or receiveselectrons and may include at least one material among materials used aselectrodes in the related art, such as carbon, aluminum, platinum, Au,and/or Ag.

According to one embodiment of the present application, a blockingsubstance 1221 and a second capturing substance 1222 may be disposed onthe first electrode 1220. Alternatively, the biosensor 1000 may also bemanufactured in the form in which the blocking substance 1221 is notfixed on the first electrode 1220, the second capturing substance 1222is not disposed thereon, or another material is further formed thereon.

The blocking substance 1221 may be a material which prevents the targetsubstance included in the sample from being adhered into the firstelectrode 1220. The blocking substance 1221 may be a material whichprevents the target substance included in the sample from being fixed tothe first electrode 1220. The blocking substance 1221 may be a materialwhich prevents other materials other than the target substance includedin the sample (i.e., non-target substances) from being adhered into thefirst electrode 1220. In other words, the blocking substance 1221 may bea material which prevents the non-target substance from being fixed tothe first electrode 1220. For example, the blocking substance 1221 maybe a protein such as BSA (bovine serum albumin), a saccharide such assucrose, or a detergent such as Tween-20 or Triton X-100.

The blocking substance 1221 may be disposed on the first electrode 1220.The blocking substance 1221 may be disposed in at least a portion of aregion of the first electrode 1220. The blocking substance 1221 may befixed in at least a portion of the region of the first electrode 1220.

In the biosensor 1000 including the magnetic nanoparticle complex 1210,it may be essential for the biosensor 1000 to be manufactured in theform in which the blocking substance 1221 is disposed on the firstelectrode 1220. In this regard, a description thereof will be made indetail below together with a result graph according to an experiment.

The second capturing substance 1222 may be a material which isspecifically bound with a second target substance. For example, thesecond target substance may be a target substance (that is, a materialto be detected, which is included in the sample). In this case, thesecond capturing substance 1222 may be a material which is specificallybonded to the target substance.

The second capturing substance 1222 may include at least one among anantigen, an antibody, a modified antibody, an antibody analogue, anaptamer, nucleic acid (e.g., DNA, RNA), lipid, and a viral proteinantigen.

For a more specific example, when the second target substance is an“antigen,” the second capturing substance 1222 may be an antibody.Alternatively, when the second target substance is “DNA,” the secondcapturing substance 1222 may be single stranded DNA including a sequencecomplementarily binding to a single strand of the DNA (i.e., the targetsubstance).

The second capturing substance 1222 may be the same material as thefirst capturing substance 1213. In other words, when the secondcapturing substance 1222 is an anti-PSA antibody, the first capturingsubstance 1213 may be the same anti-PSA antibody.

Alternatively, the second capturing substance 1222 may be a materialdifferent from the first capturing substance 1213. In other words, whenthe second capturing substance 1222 is an anti-PSA antibody, the firstcapturing substance 1213 may react with the PSA but may be an antibodywhich is specifically bound with an epitope different from an epitopewith which the second capturing substance 1222 bind.

The second capturing substance 1222 may be fixed on the first electrode1220. Thus, after the second capturing substance 1222 is fixed on thefirst electrode 1220, the blocking substance 1221 is fixed thereon sothat the second capturing substance 1222 may not degrade improvement ofthe detection signal of the blocking substance 1221 in the biosensor1000.

Hereinafter, a method of manufacturing the first electrode 1220 to whichthe blocking substance 1221 and the second capturing substance 1222 arefixed according to one embodiment of the present application will bedescribed in detail.

1.2.1.2 Method of Manufacturing First Electrode 1220 to which BlockingSubstance 1221 and Second Capturing Substance 1222 are Fixed

Hereinafter, a method of manufacturing the first electrode 1220 to whichthe blocking substance 1221 and the second capturing substance 1222 arefixed, wherein BSA is used as the blocking substance 1221 and ananti-PSA detection antibody is used as the second capturing substance1222, will be described.

However, BSA is merely an example of the blocking substance 1221 and theanti-PSA detection antibody is merely an example of the second capturingsubstance 1222. It is obvious that the blocking substance 1221 may beeasily replaced with another blocking substance 1221 and the secondcapturing substance 1222 may be replaced with another second capturingsubstance 1222 (e.g., an antigen, an antibody, DNA, or the like withrespect to another disease) by those skilled in the art.

In order to manufacture the first electrode 1220 to which the blockingsubstance 1221 and the second capturing substance 1222 are fixedaccording to one embodiment of the present application, the anti-PSAantibody may be fixed to a screen-printed carbon electrode (SPCE)through carbodiimide crosslinking.

In one method, a surface of the carbon electrode was treated withhexamethylenediamine (HMD) at room temperature for overnight tointroduce an amine functional group. The carbon electrode was washedwith deionized water (i.e., purified water) and then was placed in amixed solution in which 0.4 M(1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride) (EDC), 0.1M sulfo-(N-hydroxysulfosuccinimide) (NHS), and 0.1 mg/ml anti-PSAantibody is mixed with IVIES buffer (pH 4.7) and incubated in acontrolled humidity chamber at room temperature for two hours.

In order to treat BSA, which is an example of the blocking substance1221, on the electrode to which the second capturing substance 1222(e.g., an anti-PSA antibody) was fixed generated through the aboveprocedure, the electrode subjected to the above procedure was treatedwith a 1% BSA solution and slowly stirring thereof, and then theelectrode was washed with a PBA solution.

Subsequently, the washed electrode, to which the blocking substance 1221(e.g., the BSA) and the second capturing substance 1222 (e.g., theanti-PSA antibody) are fixed, is blow-dried with N2 gas and then storedat a temperature of 4° C. until further use.

Through the above-described procedure, the first electrode 1220 to whichthe blocking substance 1221 and the second capturing substance 1222 arefixed according to one embodiment of the present intention may bemanufactured. The first electrode 1220 may be provided in the biosensor1000 to react with a target substance included in a sample.

The first electrode 1220 to which the blocking substance 1221 and thesecond capturing substance 1222 are fixed according to one embodiment ofthe present application may serve as a working electrode in thebiosensor 1000. A detailed function of the first electrode 1220 will beeasily understood through a detailed embodiment described in theoperation of the biosensor 1000.

1.2.3 Second Electrode 1230

The second electrode 1230 is a conductive medium which emits or receiveselectrons and may include at least one material among materials used aselectrodes in the related art, such as carbon, aluminum, platinum, Au,and/or Ag.

The second electrode 1230 may be separately disposed from the firstelectrode 1220. The second electrode 1230 may be physically separatedfrom the first electrode 1220. The second electrode 1230 may be anelectrode different from the first electrode 1220.

Here, the second electrode 1230 being different from the first electrode1220 may include a case in which material compositions constituting thefirst electrode 1220 and the second electrode 1230 are different fromeach other as well as a case in which, even when the materialcompositions constituting the first electrode 1220 and the secondelectrode 1230 are the same, there are two electrodes in which the firstelectrode 1220 and the second electrode 1230 are physically separatedand divided.

The second electrode 1230 according to one embodiment of the presentapplication may serve as a reference electrode in the biosensor 1000. Adetailed function of the second electrode 1230 will be easily understoodthrough a detailed embodiment described in the operation of thebiosensor 1000.

Contact Part 1300

The contact part 1300 may be made of a material having electricalconductivity. For example, the contact part 1300 is a conductive mediumwhich emits or receives electrons and may include at least one materialamong materials used as electrodes in the related art, such as carbon,aluminum, platinum, Au, and/or Ag.

The contact part 1300 may include a first terminal electricallyconnected to the first electrode 1220 and a second terminal electricallyconnected to the second electrode 1230. When the contact part 1300 ismade of an electrode material, the contact part 1300 may include afourth electrode electrically connected to the first electrode and afifth electrode electrically connected to the second electrode 1230.

At least a portion of the contact part 1300 may be exposed to theoutside of the biosensor 1000. For example, when the contact part 1300includes the first terminal electrically connected to the firstelectrode 1220 and the second terminal electrically connected to thesecond electrode 1230, at least a portion of the first terminal and atleast a portion of the second terminal may be exposed to the outside ofthe biosensor 1000. As another example, when the contact part 1300 ismade of an electrode material, at least a portion of the fourthelectrode electrically connected to the first electrode 1220 and atleast a portion of the fifth electrode electrically connected to thesecond electrode 1230 may be exposed to the outside of the biosensor1000.

According to one embodiment of the present application, the contact part1300 may be implemented in the form in which the first electrode 1220and the fourth electrode are formed as a single electrode and the secondelectrode 1230 and the fifth electrode are formed as a single electrode.Here, the first electrode 1220 and the fourth electrode being formed asa single electrode may mean a form in which one side of the singleelectrode is connected to the reaction part 1200 and is fixed to thesecond capturing substance 1222, and the other side of the singleelectrode is exposed to the outside of the biosensor 1000. Here, thesecond electrode 1230 and the fifth electrode being formed as a singleelectrode may mean a form in which one side of the single electrode isconnected to the reaction part 1200 and the other side of the singleelectrode is exposed to the outside of the biosensor 1000.

The contact part 1300 may have a function of performing electricalconnection to the detection device 2000 which will be described below. Aregion of the contact part 1300 exposed to the outside of the biosensor1000 may have the function of performing electrical connection to thedetection device 2000.

An electrical connection between the contact part 1300 and the detectiondevice 2000 may be implemented through a physical connection. Thecontact part 1300 may implement the electrical connection with thedetection device 2000 in the form of being inserted into the detectiondevice 2000.

The contact part 1300 according to one embodiment of the presentapplication is electrically connected to the detection device 2000 sothat a voltage applied between the first electrode 1220 and the secondelectrode 1230 may be controlled through a controller 2400 of thedetection device 2000. The contact part 1300 according to one embodimentof the present application is electrically connected to the detectiondevice 2000 to allow the detection device 2000 to detect information onvoltages and/or currents of the first electrode 1220 and the secondelectrode 1230 in the biosensor 1000.

A detailed function of the contact part 1300 according to one embodimentof the present application will be easily understood through a detailedembodiment described in the operation of the biosensor 1000.

2. Operation of Biosensor 1000

A conventionally used target detection manner of the biosensor 1000 maybe broadly classified into a sandwich manner and a competitive manner.

Therefore, in the biosensor 1000 including the magnetic nanoparticlecomplex 1210, an operation of detecting a target substance in a sampleusing a sandwich manner will be described, and only a configuration andonly an operation, which should be changed in an operation of detectinga target substance in a sample using a competitive manner, will bedescribed in detail.

2.1 General Operation of Biosensor 1000

FIG. 6 is a diagram for describing a general operation of the biosensor1000 according to one embodiment of the present application.

A sample may be provided to the sample introduction part 1100 of thebiosensor 1000. A target substance may be included in the sample. Thetarget substance and a non-target substance may be included in thesample. Here, the non-target substance may mean a material which ispresent in the sample but is not specifically bound with the firstcapturing substance 1213 and the second capturing substance 1222.

When the sample is provided to the sample introduction part 1100 of thebiosensor 1000, the sample may move along a channel in the biosensor1000. For example, a micro channel (or a micro fluidic channel) isformed in the biosensor 1000, and the sample provided to the sampleintroduction part 1100 may move due to an action of a capillary force.

The sample may pass through the sample introduction part 1100 to move tothe reaction part 1200. The magnetic nanoparticle complex 1210 may bepresent in the reaction part 1200. As described above, the magneticnanoparticle complex 1210 may include the magnetic nanoparticle 1211,the reaction substances 1212, and the first capturing substances 1213.The first capturing substance 1213 may be an antibody capable ofspecifically binding with a target substance (i.e., a first targetsubstance). In this case, the antibody may include all of fragment typeantibodies such as fragment antigen binding (Fab) including a CDRregion, fragment crystallizable (Fc), and the like and/or fullantibodies such as immunoglobulin G (IgG) and the like.

The target substance included in the sample moving from the sampleintroduction part 1100 may be specifically bound with the magneticnanoparticle complex 1210. The target substance may be bound with thefirst capturing substance 1213 of the magnetic nanoparticle complex1210. The magnetic nanoparticle complex 1210 and the target substancemay perform a binding according to an antigen-antibody reaction. Theantigen-antibody reaction may be performed in the reaction part 1200 ofthe biosensor 1000.

The first electrode 1220, to which the second capturing substance 1222is fixed, and the second electrode 1230 may be fixed to the reactionpart 1200. The magnetic nanoparticle complex 1210 bound with the targetsubstance may be captured by the second capturing substance 1222 fixedon the first electrode 1220. In other words, the second capturingsubstance 1222 fixed on the first electrode 1220 may be bound with thetarget substance (i.e., a second target substance) bound with themagnetic nanoparticle complex 1210 and, the binding between a secondcapturing substance and the target substance, so, the magneticnanoparticle complex 1210 may be captured by the second capturingsubstance 1222.

When the first capturing substance 1213 and the second capturingsubstance 1222 are antibodies, the antibody 1222 fixed on the firstelectrode 1220 may react with an antigen (i.e., a target substance) inthe sample. The antigen bound with the antibody 1222 fixed on the firstelectrode 1220 may be bound with the magnetic nanoparticle complex 1210.Alternatively, antigen is bound to the antibody 1222 to which the firstelectrode 1220 is fixed, after bound with the antibody 1222, may bebound with the antibody 1212 of the magnetic nanoparticle complex 1210.In this case, the first target substance and the second target substancemay be the same material.

When a certain period of time elapses after the sample is provided tothe sample introduction part 1100, the sample excluding the magneticnanoparticle complex 1210 and the target substance, which are capturedby the second capturing substance 1222 of the first electrode 1220, maymove downstream based on the reaction part 1200. The target substance,the non-target substance, and magnetic nanoparticle complex 1210, whichare not captured by the first electrode 1220, may move to a sampledisposal unit (not shown). A plurality of samples, which are notcaptured by the first electrode 1220, may be collected in the sampledisposal unit.

When the magnetic nanoparticle complex 1210 is captured by the secondcapturing substance 1222 fixed on the first electrode 1220, a currentvalue depending on a voltage applied to the first electrode 1220 and thesecond electrode 1230 (i.e., a current value output according to theapplied voltage) may be changed. The current value being changedaccording to the voltage applied to the first electrode 1220 and thesecond electrode 1230 may be caused by a variation in characteristic ofthe material on the first electrode 1220 or the second electrode 1230according to oxidation/reduction of the reaction substance 1212 fixed tothe magnetic nanoparticle complex 1210.

According to one embodiment of the present application, the biosensor1000 using the magnetic nanoparticle complex 1210 may be provided as adiagnostic kit of a competitive manner.

The first capturing substance 1213 of the magnetic nanoparticle complex1210 may be an antigen. When the first capturing substance 1213 is anantigen, the first capturing substance 1213 may be bound with the secondcapturing substance 1222 on the first electrode 1220 in competition withthe antigen (i.e., the target substance) in the sample. In this case,the first target substance captured by the first capturing substance1213 may be the second capturing substance 1222.

The antigen (i.e., the target substance) in the sample may also be boundwith the second capturing substance 1222 on the first electrode 1220. Inthis case, the second target substance of the second capturing substance1222 may be the first capturing substance 1213 and the antigens in thesample.

Consequently, the first capturing substance 1213 and the antigens in thesample are competitively bound with the second capturing substance 1222so that, as an amount of antigens in the sample increases, an amount ofthe first capturing substance 1213 captured by the second capturingsubstance 1222 on the first electrode 1220 may decrease.

When the magnetic nanoparticle complex 1210 is captured by the secondcapturing substance 1222 fixed on the first electrode 1220, an amount ofthe target substance (i.e., the antigen) captured by the secondcapturing substance 1222 fixed on the first electrode 1220 may decrease.Consequently, as compared with a case in which the target substance isnot included in the sample, when a plurality of the target substancesare included in the sample, the current value depending on the voltageapplied to the first electrode 1220 and the second electrode 1230 may bedetected as a small. Unlike the biosensor 1000 of the sandwich manner,when the measured detection value is small, it can be confirmed that theamount of the target substance in the sample is large.

According to another embodiment of the present application, the firstcapturing substance 1213 of the magnetic nanoparticle complex 1210 maybe an antibody. When the first capturing substance 1213 is an antibody,the first capturing substance 1213 may be bound with the antigen (i.e.,the target substance) in the sample. Alternatively, the first capturingsubstance 1213 may be bound with the second capturing substance 1222 onthe first electrode 1220. In this case, the second capturing substance1222 may be an antigen. The second target substance of the secondcapturing substance 1222 may be an antibody. In other words, the secondtarget substance of the second capturing substance 1222 may be the firstcapturing substance 1213.

The antigen (i.e., the target substance) in the sample and the secondcapturing substance 1222 fixed to the electrode may compete for thefirst capturing substance 1213.

Consequently, as the antigen in the sample increases, an amount of thefirst capturing substance 1213 bound with the second capturing substance1222 may decrease. As the antigen in the sample decreases, the firstcapturing substance 1213 bound with the second capturing substance 1222may increase.

Consequently, as compared with a case in which the target substance isnot included in the sample, when a plurality of the target substancesare included in the sample, the current value depending on the voltageapplied to the first electrode 1220 and the second electrode 1230 may bedetected as a small value. When the measured detection value is small,it can be confirmed that the amount of the target substance in thesample is large.

2.2 Operation of Biosensor 1000 According to First Embodiment

According to one embodiment of the present application, the magneticnanoparticle complex 1210 having a magnetic property may be provided inthe reaction part 1200 of the biosensor 1000. Consequently, a statecondition of the reaction part 1200 may be changed to control mobilityof the magnetic nanoparticle complex 1210.

According to one embodiment of the present application, through theprocedure of controlling the mobility of the magnetic nanoparticlecomplex 1210, other materials which are not bound with the secondcapturing substance 1222 on the first electrode 1220 (i.e., which arenot captured by the second capturing substance 1222) may be washed.

Here, the other materials may include the target substance, thenon-target substance, and the magnetic nanoparticle complex 1210 whichare not captured by the first electrode 1220.

Since the magnetic nanoparticle complex 1210 which are not captured bythe first electrode 1220 and the like are disposed in a region adjacentto the first electrode 1220, in order to solve a problem in that, eventhough the target substance is not included in the sample, a negativesignal is detected and thus a false positive is diagnosed, othermaterials are washed by varying the state condition of the reaction part1200 such that there is an advantage of deriving improvement in accuracyand sensitivity of the biosensor 1000 and reduction in background aseffects.

A method of changing the state condition of the reaction part 1200 mayinclude 1) changing a magnetic field formed in the reaction part 1200,2) changing an electric field formed in the reaction part 1200, and 3)changing the magnetic field and the electric field formed in thereaction part 1200.

For example, the magnetic field formed in the reaction part 1200 may bechanged by placing a magnet in a region adjacent to the first electrode1220 and then placing the magnet in a region opposite to the firstelectrode. A detailed operation of the biosensor 1000 related to theabove description will be described below with reference to FIG. 7.

As another example, the electric field may be changed by changing amagnitude and a frequency of a voltage applied between the firstelectrode 1220 and the second electrode 1230. As still another example,in the biosensor 1000 including a third electrode having a coil typedifferent from the first electrode 1220 and the second electrode 1230,the magnetic field and/or the electric field which is formed in thereaction part 1200 may be changed by changing a current applied to thethird electrode.

FIG. 7 is a diagram for describing an operation of a biosensor 1000according to a first embodiment of the present application.

According to one embodiment of the present application, a mechanism forforming a magnetic field may be disposed at a lower end and an upper endof the first electrode 1220 of the reaction part 1200, and turningON/OFF of the mechanism for forming a magnetic field may be controlled.

The formation of the magnetic field may also be controlled by a gapbetween the magnet and the first electrode 1220. When the gap betweenthe magnet and the first electrode 1220 is small, the magnetic field inthe reaction part 1200 becomes stronger. When the magnet is alternatelypositioned above or below the first electrode 1220, or when the turningON/OFF of the mechanism for forming a magnetic field, which ispositioned above or below, is alternately performed, movement of themagnetic nanoparticle complex 1210 is changed according to the number oftimes or a retention time.

More specifically, as a result of conducting an experiment using themagnetic nanoparticle complex 1210 according to one embodiment of thepresent application, when the magnetic nanoparticle complex 1210 islocated in the reaction part 1200 and the magnet is repeatedly locatedupward and downward from the reaction part 1200, as compared with a casein which the magnet is repeatedly located upward and downward from thereaction part 1200 one hundred times, in a case in which the magnet isrepeatedly located upward and downward from the reaction part 1200 twohundred times, a signal was slightly reduced but a relatively stablepattern was exhibited (i.e., an error bar is small). As compared with acase in which the magnet is repeatedly located upward and downward fromthe reaction part 1200 one or two hundred times, in a case in which themagnet is repeatedly located upward and downward from the reaction part1200 four hundred times, it was confirmed to show a pattern in which adetection signal become larger and stable and uniformity of thedetection signal was improved.

Hereinafter, for convenience of description, an operation of thebiosensor 1000 will be described based on the above embodiment. However,even when an arrangement position of the mechanism for forming themagnetic field is changed or, as described above, the magnetic fieldand/or the electric field is changed to change an environmentalcondition of the reaction part 1200, the operation of the biosensor 1000may be easily implemented by those skilled in the art, and thus adetailed description thereof will be omitted herein.

When the sample is provided to the sample introduction part 1100 of thebiosensor 1000, the sample may move along a channel in the biosensor1000.

According to another embodiment of the present application, although notrequired, when the sample is provided to the sample introduction part1100 of the biosensor 1000, in order to allow environmental conditioncontrol of the reaction part 1200 to be initiated, an additionalelectrode different from the first electrode 1220 and the secondelectrode 1230 may be provided in the sample introduction part 1100 ofthe biosensor 1000.

The sample may pass through the sample introduction part 1100 to move tothe reaction part 1200. The magnetic nanoparticle complex 1210 may bepresent in the reaction part 1200. When the mechanisms for generating amagnetic field positioned above or below the first electrode 1220 of thereaction part 1200 is turned off, the magnetic nanoparticle complex 1210and the sample may move from the sample introduction part 1100 in adownstream direction.

The target substance may be bound with the first capturing substance1213 of the magnetic nanoparticle complex 1210. The magneticnanoparticle complex 1210 and the target substance may perform a bindingaccording to an antigen-antibody reaction. The antigen-antibody reactionmay be performed in the reaction part 1200 of the biosensor 1000.

The target substance may be bound with the second capturing substance1222 of the first electrode 1220. The magnetic nanoparticle complex 1210bound with the target substance which is bound with the second capturingsubstance 1222 may be captured by the second capturing substance 1222 tobe involved in a variation in detection signal of the biosensor 1000.

According to one embodiment of the present application, when themechanism for generating a magnetic field positioned above the firstelectrode 1220 of the reaction part 1200 is turned off and the mechanismfor generating a magnetic field positioned below the first electrode1220 of the reaction part 1200 is turned on, movement of the magneticnanoparticle complex 1210 may be guided toward the first electrode 1220of the reaction part 1200. Through the above procedure, a reactionbetween the target substance and the first capturing substance 1213 ofthe magnetic nanoparticle complex 1210 and/or between the targetsubstance and the second capturing substance 1222 of the first electrode1220 may be improved.

Thereafter, when the mechanism for generating a magnetic fieldpositioned below the first electrode 1220 of the reaction part 1200 isturned off and the mechanism for generating a magnetic field positionedabove the first electrode 1220 of the reaction part 1200 is turned on,the movement of the magnetic nanoparticle complex 1210 may be guidedtoward the upper side of the first electrode 1220 of the reaction part1200. In such an environmental condition, a magnetic nanoparticlecomplex 1210 which is not captured by the second capturing substance1222 of the first electrode 1220 is guided toward the upper side of thefirst electrode 1220 so that the magnetic nanoparticle complex 1210which is not captured by a region adjacent to the second capturingsubstance 1222 of the first electrode 1220 may be washed. In otherwords, the magnetic nanoparticle complex 1210 which is not captured bythe second capturing substance 1222 of the first electrode 1220 isguided toward the upper side of the first electrode 1220 so that themagnetic nanoparticle complex 1210 which is not captured by the regionadjacent to the second capturing substance 1222 of the first electrode1220 may be removed.

According to another embodiment of the present application, a firstenvironmental condition, in which the mechanism for generating amagnetic field positioned above the first electrode 1220 of the reactionpart 1200 is turned off and the mechanism for generating a magneticfield positioned below the first electrode 1220 of the reaction part1200 is turned on, and a second environmental condition, in which themechanism for generating the magnetic field positioned below the firstelectrode 1220 of the reaction part 1200 is turned off and the mechanismfor generating a magnetic field positioned above the first electrode1220 of the reaction part 1200 is turned off, may be repeatedlyperformed.

In other words, in addition to the embodiment in which the firstenvironmental condition is set in the reaction part 1200, a certainperiod of time elapses, and then the second environmental condition isset in the reaction part 1200, it may be controlled such that the secondenvironmental condition is set after the first environmental conditionis set in the reaction part 1200, and then the first environmentalcondition and the second environmental condition are sequentially andrepeatedly set.

Through such a procedure, a specific binding of the target substanceincluded in the sample with the magnetic nanoparticle complex 1210 maybe performed more actively. In other words, through such a procedure, anamount of the specific binding of the target substance included in thesample with the magnetic nanoparticle complex 1210 may increase.Consequently, sensitivity of the biosensor 1000 may be improved.

When the mechanism for generating a magnetic field positioned above thefirst electrode 1220 of the reaction part 1200 is turned off and themechanism for generating a magnetic field positioned below the firstelectrode 1220 of the reaction part 1200 is turned off, the magneticnanoparticle 1211, the non-target substance, and the target substance,which are not captured by the second capturing substance 1222, may movedownstream from the reaction part 1200.

After the magnetic nanoparticle 1211, the target substance, and thenon-target substance, which are not captured by the second capturingsubstance 1222, move to the sample disposal unit located downstream fromthe reaction part 1200, the presence or absence of the target substancein the sample may be confirmed by detecting a current value depending ona voltage applied to the first electrode 1220 and the second electrode1230.

According to one embodiment of the present application, a thirdelectrode in the form of a coil may be disposed above and below thereaction part 1200. A current applied to the third electrodes disposedabove and below the reaction part 1200 is adjusted such that a magneticfield formed in the reaction part 1200 may be controlled.

FIG. 8 is an enlarged view for describing an arrangement of a thirdelectrode for providing a magnetic field according to one embodiment ofthe present application.

FIG. 8 is an enlarged view of the reaction part 1200 in the biosensor1000 shown in FIG. 2.

The third electrodes in the form of a coil may be formed above and belowthe reaction part 1200. When the biosensor 1000 is electricallyconnected to the detection device 2000, a current applied to the thirdelectrodes may be controlled.

Specifically, when a current is applied to the third electrode locatedabove the reaction part 1200, an effect similar to that in which amagnet is disposed above the reaction part 1200 may be obtained. Forexample, when a current is applied to the third electrode located abovethe reaction part 1200, the magnetic nanoparticle complex 1210 may moveto a position adjacent to the third electrode located above the reactionpart 1200. In addition, when a current is applied to the third electrodelocated below the reaction part 1200, an effect similar to that in whicha magnet is disposed below the reaction part 1200 may be obtained. Forexample, when a current is applied to the third electrode located belowthe reaction part 1200, the magnetic nanoparticle complex 1210 may moveto a position adjacent to the third electrode located below the reactionpart 1200.

As described above, the current applied to the third electrode disposedabove the reaction part 1200 and the third electrode disposed below thereaction part 1200 is controlled such that movement of the magneticnanoparticle complex 1210 may be controlled.

In some cases, the movement of the magnetic nanoparticle complex 1210may be controlled in the form of repeatedly performing an operation ofapplying a first current to the third electrode disposed above thereaction part 1200 and applying a second current to the third electrodedisposed below the reaction part 1200.

2.3 Operation of Biosensor 1000 According to Second Embodiment

A biosensor 1000 according to one embodiment of the present applicationmay include a first electrode 1220 to which a blocking substance 1221 isfixed. More specifically, the biosensor 1000 according to one embodimentof the present application may include the first electrode 1220 to whichBSA is fixed.

The BSA being fixed on the first electrode 1220, performing a blockingfunction of simply preventing a target substance contained in a samplefrom being adhered on the first electrode 1220, in addition to mayperform a function of assisting an oxidation/reduction action of thereaction substance 1212 of the magnetic nanoparticle complex 1210.

FIG. 9 is a graph for describing a variation in current over a voltageof the biosensor 1000 including the first electrode 1220 to which theBSA is fixed according to one embodiment of the present application.

Referring to FIG. 8, a sample including a target substance was providedto the biosensor 1000 including the first electrode 1220 to which theBSA was not fixed, a second capturing substance 1222 was fixed, and thendetection is performed, and as a result, it was confirmed that avariation in current according to a variation in voltage was notdetected (see B SAX in the illustrated graph).

However, when the BSA was fixed to the first electrode 1220 of the samebiosensor 1000, the sample including the target substance was providedand detection was performed, and as a result, it was confirmed that avariation in current depending on a variation in voltage was detected(see BSAO in the illustrated graph).

Through the result graph, it was confirmed that whether the targetsubstance is present in the sample may be detected using the biosensor1000 including the first electrode 1220 to which the BSA and the secondcapturing substance 1222 are fixed, and the blocking substance 1221(e.g., the BSA) may perform a function of assisting oxidation/reductionaction in the biosensor 1000 including the magnetic nanoparticle complex1210.

Detection Device 2000

1. Detection Device 2000

1.1. Configuration of Detection Device 2000

FIG. 10 is a diagram for describing a detection device 2000 according toone embodiment of the present application.

The detection device 2000 may include an electrode part 2100, a memorypart 2200, an electrical signal generation part 2300, and/or acontroller 2400. However, all the above components need not be included,and each component may be omitted or duplicated, and a detection device2000 may also be manufactured in the form of further includingcomponents in addition to the above disclosed components.

1.1.1 Electrode Part 2100

The electrode part 2100 is a conductive medium which emits or receiveselectrons and may include at least one material among materials used aselectrodes in the related art, such as carbon, aluminum, platinum, Au,and/or Ag.

The electrode part 2100 may have a function of performing electricalconnection to the contact part 1300 of the biosensor 1000. The electrodepart 2100 may include a first electrode terminal, which is electricallyconnected to the first electrode 1220 of the biosensor 1000, and asecond electrode terminal which is electrically connected to the secondelectrode 1230 of the biosensor 1000. When the contact part 1300 of thebiosensor 1000 includes a fourth electrode electrically connected to thefirst electrode and a fifth electrode electrically connected to thesecond electrode 1230, the first electrode terminal may be electricallyconnected to the first electrode 1220 and the fourth electrode, and thesecond electrode terminal may be electrically connected to the secondelectrode 1230 and the fifth electrode.

The electrode part 2100 according to one embodiment of the presentapplication is electrically connected to the biosensor 1000 to allow thedetection device 2000 to detect information on voltages and/or currentsof the first electrode 1220 and the second electrode 1230 in thebiosensor 1000.

The electrode part 2100 according to one embodiment of the presentapplication may be electrically connected to the biosensor 1000 toperform a function of transferring electrical energy (e.g., a voltageand/or a current) generated in the detection device 2000 to the firstelectrode 1220 and the second electrode 1230 of the biosensor 1000.

According to one embodiment of the present application, the electrodepart 2100 may be physically connected to the contact part 1300 of thebiosensor 1000. The biosensor 1000 is insertion-coupled to a portion ofthe detection device 2000 so that the contact part 1300 of the biosensor1000 may be in contact with the electrode part 2100 of the detectiondevice 2000.

A function of the electrode part 2100 according to one embodiment of thepresent application will be easily understood through a detailedembodiment described in an operation of the detection device 2000.

1.1.2 Memory Part 2200

The memory part 2200 may perform a function of temporarily ornon-temporarily storing information.

For example, the memory part 2200 may be implemented in the form ofincluding a hard disk drive (HDD), a solid state drive (SSD), a flashmemory, a read-only memory (ROM), and/or a random access memory (RAM).As another example, the memory part 2200 may be implemented in the formof being connected to another server through wireless communication tostore necessary information in another server. The present disclosure isnot limited thereto, and a functional unit which performs a function ofstoring information to allow the detection device 2000 to utilize theinformation may correspond to the memory part 2200 regardless of whetherthe functional unit has a hardware or software structure.

The memory part 2200 according to one embodiment of the presentapplication may store information on voltage values which are to beapplied to the first electrode 1220 and the second electrode 1230 of thebiosensor 1000. In order to detect current values depending on voltagesapplied to the first electrode 1220 and the second electrode 1230 todetect whether a target substance is included in a sample introducedinto the biosensor 1000, the memory part 2200 may store information onvoltage values of the first electrode 1220 and the second electrodes1230, wherein the voltage values should be applied thereto.

A function of the memory part 2200 according to one embodiment of thepresent application will be easily understood through a detailedembodiment described in the operation of the detection device 2000.

1.1.3 Electrical Signal Generation Part 2300

The electrical signal generation part 2300 may perform a function ofgenerating a voltage and/or a current. For example, the electricalsignal generation part 2300 may include direct current (DC)voltage/current generators. As another example, the electrical signalgeneration part 2300 may include a pulse width modulation (PWM) outputgenerator. As still another example, the electrical signal generationpart 2300 may include an alternating current (AC) standard voltagegenerator.

The electrical signal generation part 2300 may be implemented in theform of an electronic circuit such as an integrated circuit whichperforms a function of generating a voltage and/or a current and,alternatively, in the form of a computer or a device similar to thecomputer according to hardware, software, or a combination thereof.According to one embodiment of the present application, the electricalsignal generation part 2300 may be implemented in the form of beingincluded in the controller 2400.

A function of the electrical signal generation part 2300 according toone embodiment of the present application will be easily understoodthrough a detailed embodiment described in the operation of thedetection device 2000.

1.1.4 Controller 2400

The controller 2400 may control an overall operation of the detectiondevice 2000. To this end, the controller 2400 may perform calculationand processing on various pieces of information and control operationsof components of the detection device 2000.

The controller 2400 may be implemented as a computer or a device similarto the computer according to hardware, software, or a combinationthereof. In terms of hardware, the controller 2400 may be provided inthe form of an electronic circuit such as a central processing unit(CPU) chip which processes an electrical signal and performs a controlfunction. In terms of software, the controller 2400 may be provided inthe form of a program which drives the controller 2400 in terms ofhardware.

The controller 2400 may control the electrical signal generation part2300 to provide a voltage and/or a current to the biosensor 1000 throughthe electrode part 2100.

In order to detect a current depending on a variation in voltage appliedto the first electrode 1220 and the second electrode 1230 of thebiosensor 1000 and determine whether a target substance is captured by asample introduced into the biosensor 1000, the controller 2400 accordingto one embodiment of the present application may control a voltageincluding a first stage of increasing a voltage applied between thefirst electrode 1220 and the second electrode 1230 and a second stage ofdecreasing the voltage to be provided. This may be to provide acirculating voltage to perform qualitative analysis and/or quantitativeanalysis of the target substance included in the sample.

In order to stabilize a curve of the current, the controller 2400according to one embodiment of the present application may control avoltage, which is applied as a voltage that is higher than at least oneof the lowest voltage in the first stage and the lowest voltage in thesecond stage for a predetermined time or more, to be provided.

Here, the stabilization means that, in a current graph according to avoltage in an operation of providing the circulating voltage, apotential/reduction potential is relatively increased when a current ismaximum and/or a potential/oxidation potential value is relativelydecreased when the current is minimum. Alternatively, the stabilizationmeans that, in the current graph according to the voltage in theoperation of providing the circulating voltage, a maximum current valueis relatively increased and/or a minimum current value is relativelydecreased. Alternatively, the stabilization means that, in the currentgraph according to the voltage in the operation of providing thecirculating voltage, a current depending on oxidation (a currentaccording to an increase of a voltage) corresponding to a voltage of 0 Vand a current depending on reduction (a current according to a decreaseof the voltage) coincide with each other relatively more.

The controller 2400 according to one embodiment of the presentapplication may control the environmental condition of the reaction part1200 of the biosensor 1000 to be changed through the electrode part 2100or a separate magnetic field forming mechanism. For example, thecontroller 2400 controls an electrical signal provided to the firstelectrode 1220, the second electrode 1230, and/or the third electrode,which is electrically connected to the electrode part 2100, to changethe environmental condition of the reaction part 1200 of the biosensor1000. As another example, the controller 2400 may control turning ON/OFFof the separate magnetic forming mechanism included in the detectiondevice 2000 to change the environmental condition of the reaction part1200 of the biosensor 1000.

Hereinafter, unless otherwise specified, it may be construed that anoperation of the detection device 2000 is performed under the control ofthe controller 2400. A function of the controller 2400 according to oneembodiment of the present application will be easily understood througha detailed embodiment described in the operation of the detection device2000.

1.2 Operation of Detection Device 2000

FIG. 11 is a diagram for describing an operation of the detection device2000 according to one embodiment of the present application.

According to one embodiment of the present application, when a firstsignal is received (S1000), the detection device 2000 may provide asecond signal (S2000) and may detect a third signal (S3000). However,each operation is not necessarily performed, and each operation may beomitted or repeated, and other procedures may be additionally performed.

1.2.1 Receiving First Signal (S1000)

According to one embodiment of the present application, the detectiondevice 2000 may receive the first signal (S1000). For example, the firstsignal may mean a signal received when a sample is introduced to thesample introduction part 1100 of the biosensor 1000 through a separateelectrode or the like which is additionally provided in the biosensor1000. As another example, the first signal may mean a signal receivedwhen the sample reaches the reaction part 1200 of the biosensor 1000through the separate electrode or the like which is additionallyprovided in the biosensor 1000. As still another example, the firstsignal may mean a signal received when the sample reaches the reactionpart 1200 of the biosensor 1000 through the first electrode 1220 and/orthe second electrode 1230 of the biosensor 1000. As yet another example,the first signal may mean a signal received when the sample reaches thesample disposal unit of the biosensor 1000 through the first electrode1220 and/or the second electrode 1230 of the biosensor 1000.

When the first signal is received, the controller 2400 of the detectiondevice 2000 may begin to provide the second signal (S2000).

1.2.2 Providing Second Signal (S2000)

According to one embodiment of the present application, the detectiondevice 2000 may provide the second signal (S2000).

For example, the second signal may be a signal by which the detectiondevice 2000 controls one operation of the biosensor 1000. An example ofthe second signal may mean 1) a signal transmitted to the biosensor 1000so as to change the environmental condition of the reaction part 1200 ofthe biosensor 1000, 2) in order to determine whether the targetsubstance is captured in the sample introduced into the biosensor 1000by detecting a current depending on a variation in voltage applied tothe first electrode 1220 and the second electrode 1230 of the biosensor1000, a signal transmitted to the biosensor 1000 so as to provide avoltage including a first stage of increasing a voltage applied betweenthe first electrode 1220 and the second electrode 1230 and a secondstage of decreasing the voltage applied therebetween, and/or 3) in orderto stabilize the curve of the current, a signal transmitted to thebiosensor 1000 so as to provide a voltage which is higher than at leastone of the lowest voltage in the first stage and the lowest voltage inthe second stage and is applied for a predetermined time or more.

FIG. 12 is a diagram for describing the provision of the second signal(S2000) according to one embodiment of the present application.

According to one embodiment of the present application, the detectiondevice 2000 may provide a second-first signal (S2100), provide asecond-second signal (S2200), and provide a second-third signal (S2300).However, each operation is not necessarily performed, and each operationmay be omitted or repeated, and other procedures may be additionallyperformed.

The provision of the second-first signal (S2100) may mean an operationin which an electrical signal is transmitted from the detection device2000 to the biosensor 1000 in order to change the environmentalcondition of the reaction part 1200 of the biosensor 1000.

For example, the controller 2400 provides an electrical signal forchanging magnitudes, frequencies, and the like of the voltages appliedto the first electrode 1220 and the second electrode 1230 to change theenvironmental condition of the reaction part 1200 of the biosensor 1000so that movement of the magnetic nanoparticle complex 1210, the targetsubstance, and/or the non-target substance, which are located in thereaction part 1200 of the biosensor 1000, may be changed.

As another example, the controller 2400 provides an electrical signalfor changing a current applied to the coil-shaped third electrodeincluded in the biosensor 1000 to change the environmental condition ofthe reaction part 1200 of the biosensor 1000 so that movement of themagnetic nanoparticle complex 1210, the target substance, and/or thenon-target substance, which are located in the reaction part 1200 of thebiosensor 1000, may be changed.

The provision of the second-second signal (S2200) may mean an operationin which, prior to the provision of the second-third signal (S2300), anelectrical signal for applying a specific voltage is transmitted fromthe detection device to the biosensor 1000 so as to stabilize the curveof the current according to the provision of the second-third signal(S2300).

For example, prior to detection of the presence or absence of the targetsubstance from the curve of the current according to the second-thirdsignal, the provision of the second-second signal (S2200) may perform afunction of inducing oxidation/reduction reactions of the magneticnanoparticle complex 1210 captured by second capturing substance of thefirst electrode 1220 and stabilizing the curve of the current accordingto the second-third signal.

According to the provision of the second-second signal (S2200), specificvoltages are applied to the first electrode 1220 and the secondelectrode 1230 of the biosensor 1000 for a predetermined time or more sothat and the reaction substance 1212 of the magnetic nanoparticlecomplex 1210 undergoes oxidation pretreatment. For example, according tothe provision of the second-second signal (S2200), a voltage of at least1 V or more may be applied between the first electrode 1220 and thesecond electrode 1230 of the biosensor 1000 for at least two seconds. Asanother example, according to the provision of the second-second signal(S2200), a voltage of 1.5 V may be applied between the first electrode1220 and the second electrode 1230 of the biosensor 1000 for tenseconds.

According to the provision of the second-second signal (S2200), specificvoltages are applied to the first electrode 1220 and the secondelectrode 1230 of the biosensor 1000 for a predetermined time or more sothat the reaction substance 1212 of the magnetic nanoparticle complex1210 may undergo oxidation pretreatment, and then the voltage to whichapplied to the first electrode 1220 and the second electrode 1230 of thebiosensor 1000 is decreased so that the reaction substance 1212 of themagnetic nanoparticle complex 1210 may undergo reduction pretreatment.For example, according to the provision of the second-second signal(S2200), a voltage of at least 1 V or more is applied between the firstelectrode 1220 and the second electrode 1230 of the biosensor 1000 forat least two seconds, and then a voltage which decreases the voltagebetween the first electrode 1220 and the second electrode 1230 from atleast 1 V or more to at least 0 V or less may be applied. As anotherexample, according to the provision of the second-second signal (S2200),a voltage of 1.5 V is applied between the first electrode 1220 and thesecond electrode 1230 of the biosensor 1000 for ten seconds, and thenthe voltage applied to the first electrode 1220 and the second electrode1230 may be decreased from 1.5 V to −0.2 V at a rate of −0.1 V/s.

According to the provision of the second-second signal (S2200), thespecific voltages are applied to the first electrode 1220 and the secondelectrode 1230 of the biosensor 1000 for a predetermined time or more sothat the reaction substance 1212 of the magnetic nanoparticle complex1210 may undergo oxidation pretreatment, and then the voltages to whichapplied to the first electrode 1220 and the second electrode 1230 of thebiosensor 1000 are decreased so that the reaction substance 1212 of themagnetic nanoparticle complex 1210 may undergo reduction pretreatment.Thereafter, the voltages to which applied to the first electrode 1220and the second electrode 1230 of the biosensor 1000 are increased sothat the reaction substance 1212 of the magnetic nanoparticle complex1210 may undergo oxidation pretreatment. For example, according to theprovision of the second-second signal (S2200), the voltage of at least 1V or more is applied between the first electrode 1220 and the secondelectrode 1230 of the biosensor 1000 for at least two seconds, and thenthe voltage which decreases the voltage between the first electrode 1220and the second electrode 1230 from at least 1 V or more to at least 0 Vor less may be applied. Thereafter, a voltage which increases thevoltage between the first electrode 1220 and the second electrode 1230from at least 0 V to at least 1 V may be applied. As another example,according to the provision of the second-second signal (S2200), thevoltage of 1.5 V is applied between the first electrode 1220 and thesecond electrode 1230 of the biosensor 1000 for ten seconds, and thenthe voltages applied to the first electrode 1220 and the secondelectrode 1230 may be decreased from 1.5 V to −0.2 V at a rate of −0.1V/s. Thereafter, the voltages applied to the first electrode 1220 andthe second electrode 1230 may be increased from −0.2 V to 1.5 V at arate of 0.1 V/s.

The provision of the second-third signal (S2300) may mean an operationin which, in order to determine whether the target substance is capturedby the sample introduced into the biosensor 1000 by detecting a currentaccording to a variation in voltage applied to the first electrode 1220and the second electrode 1230 of the biosensor 1000, a signal forproviding a voltage including a first stage of increasing a voltageapplied between the first electrode 1220 and the second electrode 1230and a second stage of decreasing the voltage applied therebetween istransmitted from the detection device to the biosensor 1000.

FIG. 13 is a diagram for describing the provision of the second-thirdsignal (S2300) according to one embodiment of the present application.

For example, in order to perform analysis on whether the targetsubstance is included in the sample (qualitative analysis) and/or arelative amount of the target substance included in the sample(quantitative analysis) using cyclic voltammetry, the provision of thesecond-third signal (S2300) may perform a function of providing aswitching voltage including a rising potential and a falling potentialof a voltage during at least one period T.

According to the provision of the second-third signal (S2300), thevoltages applied to the first electrode 1220 and the second electrode1230 of the biosensor 1000 are increased and then decreased so that thedetection device 2000 may acquire a detection value depending onoxidation of the reaction substance 1212 of the magnetic nanoparticlecomplex 1210 and acquire a detection value depending on reduction of thereaction substance 1212 of the magnetic nanoparticle complex 1210. Forexample, according to the provision of the second-third signal (S2300),a voltage which increases the voltage between the first electrode 1220and the second electrode 1230 of the biosensor 1000 from at least 0 V orless to at least 1 V or more may be applied, and then a voltage whichdecreases the voltage between the first electrode 1220 and the secondelectrode 1230 from at least 1 V or more to at least 0 V or less may beapplied. As another example, according to the provision of thesecond-third signal (S2300), the voltages applied to the first electrode1220 and the second electrode 1230 of the biosensor 1000 may beincreased from 0.0 V to 1.2 V at a rate of 0.1 V/s and, subsequently,the voltages applied to the first electrode 1220 and the secondelectrode 1230 may be decreased from 1.2 V to 0.0 V at a rate of −0.1V/s.

According to the provision of the second-third signal (S2300), thevoltages applied to the first electrode 1220 and the second electrode1230 of the biosensor 1000 are decreased and then increased so that thedetection device 2000 may acquire a detection value according toreduction of the reaction substance 1212 of the magnetic nanoparticlecomplex 1210 and acquire a detection value depending on oxidation of thereaction substance 1212 of the magnetic nanoparticle complex 1210. Forexample, according to the provision of the second-third signal (S2300),a voltage which decreases the voltage between the first electrode 1220and the second electrode 1230 of the biosensor 1000 from at least 1 V ormore to at least 0 V or less may be applied and, subsequently, a voltagewhich increases the voltage between the first electrode 1220 and thesecond electrode 1230 from at least 0 V or less to at least 1 V or moremay be applied. As another example, according to the provision of thesecond-third signal (S2300), the voltages applied to the first electrode1220 and the second electrode 1230 of the biosensor 1000 may bedecreased from 1.2 V to 0.0 V at a rate of −0.1 V/s and, subsequently,the voltages applied to the first electrode 1220 and the secondelectrode 1230 may be increased from 0.0 V to 1.2 V at a rate of 0.1V/s.

1.2.3 Detecting Third Signal (S3000)

According to one embodiment of the present application, the detectiondevice 2000 may detect the third signal (S3000). For example, thedetection of the third signal may mean an operation in which thedetection device 2000 detects the currents of the first electrode 1220and the second electrode 1230 of the biosensor 1000 according to theprovision of the second-third signal (S2300).

More specifically, when the provision of the second-third signal (S2300)is to analyze the presence or absence of the target substance usingcyclic voltammetry, a current graph according to the rising potentialand the falling potential of the first electrode 1220 and the secondelectrode 1230, which are acquired from the detection of the thirdsignal due to the provision of the second-third signal (S2300), isconfirmed to have a maximum current value and a minimum current value sothat it is possible to determine the presence of the target substance inthe sample.

1.3 Operation of Detection Device 2000 According to Third Embodiment

FIG. 14 is a diagram for describing an operation of performing areduction pretreatment prior to the provision of the second-third signal(S2300) according to a third embodiment of the present application.

The detection device 2000 according to one embodiment of the presentapplication may operate such that the voltages applied to the firstelectrode 1220 and the second electrode 1230 of the biosensor 1000according to the provision of the second-third signal (S2300) areincreased from 0.0 V to 1.2 V at a rate of 0.1 V/s and, subsequently,when the second-third signal is provided such that the voltages appliedto the first electrode 1220 and the second electrode 1230 are decreasedfrom 1.2 V to 0.0 V at a rate of −0.1 V/s, the reaction part 1200 of thebiosensor 1000 undergoes reduction pretreatment prior to the provisionof the second-third signal (S2300).

Prior to the provision of the second-third signal (S2300), the provisionof the second-second signal (S2200) may be performed such that thereaction part 1200 of the biosensor 1000 undergoes reductionpretreatment.

The detection device 2000 according to one embodiment of the presentapplication may operate such that a voltage of 1.5 V is applied to thefirst electrode 1220 and the second electrode 1230 of the biosensor 1000for ten seconds according to the provision of the second-second signaland, subsequently, the voltage applied to the first electrode 1220 andthe second electrode 1230 is decreased from 1.5 V to −0.2 Vat a rate of−0.1 V/s.

FIG. 15 is a diagram for describing a detection graph of a third signalaccording to the provision of the second-second signal (S2200) and theprovision of the second-third signal (S2300) according to one embodimentof the present application.

Line A of FIG. 15 shows a current graph according to a voltage due tothe second-third signal when the voltages applied to the first electrode1220 and the second electrode 1230 of the biosensor 1000 are increasedfrom 0.0 V to 1.2 V at a rate of 0.1 V/s according to the provision ofthe second-third signal (S2300), and when the second-third signal isprovided such that the voltages applied to the first electrode 1220 andthe second electrode 1230 are decreased from 1.2 V to 0.0 V at a rate of−0.1 V/s, prior to the provision of the second-third signal (S2300),voltages of 1.5 V are applied to the first electrode 1220 and the secondelectrode 1230 of the biosensor 1000 for ten seconds according to theprovision of the second-second signal (S2200), and the voltages appliedto the first electrode 1220 and the second electrode 1230 are decreasedfrom 1.5 V to −0.2 V at a rate of −0.1 V/s and then increased from −0.2V to 1.5 V at a rate of 0.1 V/s.

Line B of FIG. 15 shows a current graph according to the voltage due tothe second-third signal when the voltages corresponding to the voltagegraph over time shown in FIG. 13 are applied to the first electrode 1220and the second electrode 1230.

Line C of FIG. 15 shows a current graph according to the voltage due tothe second-third signal when the voltages applied to the first electrode1220 and the second electrode 1230 of the biosensor 1000 are increasedfrom 0.0 V to 1.2 V at a rate of 0.1 V/s according to the provision ofthe second-third signal (S2300), and when the second-third signal isprovided such that the voltages applied to the first electrode 1220 andthe second electrode 1230 are decreased from 1.2 V to 0.0 V at a rate of−0.1 V/s, prior to the provision of the second-third signal (S2300),voltages of 1.5 V are applied to the first electrode 1220 and the secondelectrode 1230 of the biosensor 1000 for ten seconds according to theprovision of the second-second signal (S2200).

Referring to FIG. 15, it can be confirmed that a maximum current valuein a voltage-current graph corresponding to line B was increased ascompared with maximum current value in voltage-current graphscorresponding to line A and maximum current value in voltage-currentgraphs corresponding to line C.

In addition, referring to FIG. 15, it can be confirmed that apotential/reduction potential when the current is maximum in thevoltage-current graph corresponding to line B was increased as comparedwith potential/reduction potential when the current is maximum in thevoltage-current graph corresponding to line A and potential/reductionpotential when the current is maximum in the voltage-current graphcorresponding to line C.

Further, referring to FIG. 15, it can be confirmed that a current due tooxidation and a current due to reduction, which correspond to a voltageof 0 V in the voltage-current graph corresponding to line B, furthercoincide with each other relatively, compared with to thevoltage-current graphs corresponding to lines A and C.

1.4 Operation of Detection Device 2000 According to Fourth Embodiment

In the operation of the detection device 2000 according to the thirdembodiment, when the current due to oxidation was detected and then thecurrent due to the reduction was detected according to the second-thirdsignal, and the reduction pretreatment was performed prior to theprovision of the second-third signal, it was confirmed that the detectedvalue depending on the second-third signal was stabilized.

In an operation of the detection device 2000 according to the fourthembodiment, when a current due to reduction is detected and then thecurrent due to the oxidation is detected according to the second-thirdsignal, an example in which oxidation pretreatment is performed so as toacquire a detected value depending on the stabilized second-third signalwill be described.

FIG. 16 is a diagram for describing an operation of performing oxidationpretreatment prior to the provision of the second-third signal (S2300)according to the fourth embodiment of the present application.

The detection device 2000 according to one embodiment of the presentapplication may operate such that the voltages applied to the firstelectrode 1220 and the second electrode 1230 of the biosensor 1000 aredecreased from 1.2 V to 0.0 V at a rate of −0.1 V/s according to theprovision of the second-third signal (S2300) and, subsequently, when thesecond-third signal (S2300) is provided such that the voltages appliedto the first electrode 1220 and the second electrode 1230 are increasedfrom 0.0 V to 1.2 V at a rate of 0.1 V/s, the reaction part 1200 of thebiosensor 1000 undergoes reduction pretreatment prior to the provisionof the second-third signal (S2300).

Prior to the provision of the second-third signal (S2300), the provisionof the second-second signal (S2200) may be performed such that thereaction part 1200 of the biosensor 1000 undergoes oxidationpretreatment.

The detection device 2000 according to one embodiment of the presentapplication may operate such that a voltage of 1.5 V may be applied tothe first electrode 1220 and the second electrode 1230 of the biosensor1000 for ten seconds according to the provision of the second-secondsignal (S2200).

The detection device 2000 according to one embodiment of the presentapplication may operate such that the voltage of 1.5 V is applied to thefirst electrode 1220 and the second electrode 1230 of the biosensor 1000for ten seconds according to the provision of the second-second signal(S2200) and, subsequently, the voltage applied to the first electrode1220 and the second electrode 1230 may be decreased from 1.5 V to −0.2 Vat a rate of −0.1 V/s and then increased from −0.2 V to 1.5 V at a rateof 0.1 V/s.

The detection device 2000 according to one embodiment of the presentapplication may operate such that the voltage of 1.5 V is applied to thefirst electrode 1220 and the second electrode 1230 of the biosensor 1000for ten seconds according to the provision of the second-second signal(S220) and, subsequently, the voltage applied to the first electrode1220 and the second electrode 1230 is increased from −0.2 V to 1.5 V ata rate of 0.1 V/s.

Consequently, when the voltage applied to the first electrode 1220 andthe second electrode 1230 of the biosensor 1000 is increased from 0.0 Vto 1.2 V at a rate of 0.1 V/s according to the provision of thesecond-third signal (S2300), and then when the second-third signal isprovided (S2300) such that the voltage applied to the first electrode1220 and the second electrode 1230 is decreased from 1.2 V to 0.0 V at arate of −0.1 V/s, as in the graph shown in FIG. 15, the most stabilizedcurrent graph according to the voltage due to the second-third signalmay be acquired.

As described above, the method of analyzing the presence or absence ofthe target substance using cyclic voltammetry according to someembodiments of the present application has been disclosed in detail.However, according to one embodiment of the present application, it isalso possible to analyze the presence or absence of the target substanceusing differential pulse voltammetry.

For a specific example, in the provision of the second-third signal(S2300) and the detection of the third signal (S3000), a pulse signalmay be provided at a time of the provision of the second-third signal(S2300) in the form of a voltage having 1) a step potential of 4 mV in arange of 1 v to 0 V, 2) a modulation amplitude of −50 mV, 3) amodulation time of 5 seconds, and 4) an interval time of 200 ms.

Consequently, in the detection of the third signal (S3000), a graph of acurrent depending on an applied pulse may be illustrated, and whetherthe illustrated graph has a maximum current value or a minimum currentvalue is determined so that the presence of the target substance in thesample may be determined.

As described above, although a configuration and a feature of thepresent application have been described on the basis of the embodimentsaccording to the present application, the present application is notlimited thereto, and it is apparent to those skilled in the art thatvarious alternations or modifications can be made within the spirit andscope of the present application. Therefore, it is noted that thesealternations or modifications fall within the scope of the appendedclaims.

What is claimed is:
 1. A biosensor for detecting a target antigen, thebiosensor comprising: a sample introduction part; a reaction partcomprising a first electrode, wherein a first antibody is positioned onthe first electrode, the first electrode is configured to electricallyconnect with an electrode of a detection device; and a magneticnanoparticle complex comprising a second antibody, a reaction substanceand a magnetic nanoparticle, wherein the magnetic nanoparticle has amagnetic property, and the second antibody and the reaction substanceare positioned on the magnetic nanoparticle; wherein the sampleintroduction part is configured to make fluidic connect with thereaction part such that a sample introduced through the sampleintroduction part moves to the reaction part; wherein the first antibodypositioned on the first electrode specifically binds to the targetantigen, wherein the second antibody of the magnetic nanoparticlecomplex specifically binds to the target antigen, and wherein thereaction substance has a property that induces a change of a currentaccording to a voltage applied between the first electrode and a secondelectrode when the reaction substance is near the first electrode, torepresent the target antigen is included in the sample.
 2. The biosensorof claim 1, wherein the reaction substance performs an oxidationreaction or a reduction reaction when a predetermined condition issatisfied at which near the first electrode.
 3. The biosensor of claim2, wherein the second electrode is separated from the first electrode,and wherein the predetermined condition is formed by the voltage appliedbetween the first electrode and the second electrode.
 4. The biosensorof claim 1, wherein the reaction substance is a metal particle.
 5. Thebiosensor of claim 4, wherein the reaction substance is a gold particleor a silver particle.
 6. The biosensor of claim 1, wherein the reactionsubstance is fixed to the magnetic nanoparticle and the second antibodyis fixed to the reaction substance.
 7. The biosensor of claim 1, whereinthe reaction part further comprises a third electrode, the thirdelectrode is separated from the first electrode, wherein a position ofthe magnetic nanoparticle complex is controlled by an electrical fieldof the reaction part, and wherein the electrical field is formed by avoltage applied between the first electrode and the third electrode. 8.The biosensor of claim 1, wherein the reaction part further comprises athird electrode, the third electrode is separated from the firstelectrode, wherein a position of the magnetic nanoparticle complex iscontrolled by a magnetic field of the reaction part, and wherein themagnetic field is formed by a current voltage applied on the thirdelectrode.
 9. The biosensor of claim 1, wherein the first antibody issame substance with the second antibody.
 10. The biosensor of claim 1,wherein when the target antigen is included in the sample, the secondantibody of the magnetic nanoparticle complex is immovable to the firstantibody positioned on the first electrode, and wherein when the secondantibody is immovable to the first electrode indirectly, the reactionsubstance induces the change of a current in response to an electricalcondition of the reaction part.
 11. A biosensor for detecting a targetantigen, the biosensor comprising: a sample introduction part; areaction part comprising a first electrode, wherein a first antibody ispositioned on the first electrode, the first electrode is configured toelectrically connect with an electrode of a detection device; and amagnetic nanoparticle complex comprising a first antigen, a reactionsubstance and a magnetic nanoparticle, wherein the magnetic nanoparticlehas a magnetic property, and the first antigen and the reactionsubstance are positioned on the magnetic nanoparticle; wherein thesample introduction part is configured to make fluidic connect with thereaction part such that a sample introduced through the sampleintroduction part moves to the reaction part; wherein the first antibodypositioned on the first electrode specifically binds to the targetantigen, wherein the first antigen of the magnetic nanoparticle complexspecifically binds to the first antibody, and wherein the reactionsubstance has a property that induces a change of a current according toa voltage applied between the first electrode and a second electrodewhen the reaction substance is near the first electrode, to representthe target antigen is included in the sample.
 12. The biosensor of claim11, wherein the reaction substance performs an oxidation reaction or areduction reaction when a predetermined condition is satisfied at whichnear the first electrode.
 13. The biosensor of claim 12, wherein thesecond electrode is separated from the first electrode, and wherein thepredetermined condition is formed by the voltage applied between thefirst electrode and the second electrode.
 14. The biosensor of claim 11,wherein the reaction substance is a metal particle.
 15. The biosensor ofclaim 14, wherein the reaction substance is a gold particle or a silverparticle.
 16. The biosensor of claim 11, wherein the reaction substanceis fixed to the magnetic nanoparticle and the first antigen is fixed tothe reaction substance.
 17. The biosensor of claim 11, wherein thereaction part further comprises a third electrode, the third electrodeis separated from the first electrode, wherein a position of themagnetic nanoparticle complex is controlled by an electrical field ofthe reaction part, and wherein the electrical field is formed by avoltage applied between the first electrode and the third electrode. 18.The biosensor of claim 11, wherein the reaction part further comprises athird electrode, the third electrode is separated from the firstelectrode, wherein a position of the magnetic nanoparticle complex iscontrolled by a magnetic field of the reaction part, and wherein themagnetic field is formed by a current voltage applied on the thirdelectrode.
 19. The biosensor of claim 11, wherein the first antigen issame substance with the target antigen.
 20. The biosensor of claim 11,wherein when the target antigen is included in the sample, the targetantigen disturbs a binding the first antigen and the first antibodypositioned on the first electrode, and wherein when the first antigen isimmovable to the first electrode indirectly, the reaction substanceinduces the change of a current in response to an electrical conditionof the reaction part.
 21. A biosensor for detecting a target antibody,the biosensor comprising: a sample introduction part; a reaction partcomprising a first electrode, wherein a first antigen is positioned onthe first electrode, the first electrode is configured to electricallyconnect with an electrode of a detection device; and a magneticnanoparticle complex comprising a second antibody, a reaction substanceand a magnetic nanoparticle, wherein the magnetic nanoparticle has amagnetic property, and the second antibody and the reaction substanceare positioned on the magnetic nanoparticle; wherein the sampleintroduction part is configured to make fluidic connect with thereaction part such that a sample introduced through the sampleintroduction part moves to the reaction part; wherein the first antigenpositioned on the first electrode specifically binds to the targetantibody, wherein the second antibody of the magnetic nanoparticlecomplex specifically binds to the first antigen, and wherein thereaction substance has a property that induces a change of a currentaccording to a voltage applied between the first electrode and a secondelectrode when the reaction substance is near the first electrode, torepresent the target antibody is included in the sample.
 22. A biosensorfor detecting a target antibody, the biosensor comprising: a sampleintroduction part; a reaction part comprising a first electrode, whereina first antigen is positioned on the first electrode, the firstelectrode is configured to electrically connect with an electrode of adetection device; and a magnetic nanoparticle complex comprising asecond antigen, a reaction substance and a magnetic nanoparticle,wherein the magnetic nanoparticle has a magnetic property, and thesecond antigen and the reaction substance are positioned on the magneticnanoparticle; wherein the sample introduction part is configured to makefluidic connect with the reaction part such that a sample introducedthrough the sample introduction part moves to the reaction part; whereinthe first antigen positioned on the first electrode specifically bindsto the target antibody, wherein the second antigen of the magneticnanoparticle complex specifically binds to the target antibody, andwherein the reaction substance has a property that induces a change of acurrent according to a voltage applied between the first electrode and asecond electrode when the reaction substance is near the firstelectrode, to represent the target antibody is included in the sample.